The present invention relates to a connecting device for use in connecting a high-pressure gas supply unit to an endoscope, in checking the endoscope for gastightness.
in general, all parts of an endoscope; including an operating section and a universal cord coupled thereto, as well as an insert section, are in danger of being contaminated during use. Therefore, the entire endoscope is made gastight, and, after use, is immersed in a medical fluid for disinfection. During disinfection, if the insert section formed of a flexible tube or the universal cord has pinholes or cracks; after disinfection, the disinfectant or wash water may possibly soak into the endoscope, damaging optical system, etc.
Conventionally, therefore, the operating section or other sections of the endoscope are provided with a communicating section for connecting the inside and outside of the endoscope. Gas is fed into the endoscope through the communicating section to pressurize the interior of the endoscope. Then, the endoscope is immersed in water to be checked for the leakage of the gas in the form of bubbles. In so doing, a gas supply unit is connected to the endoscope, to supply the gas thereto. In connecting the endoscope and the gas supply unit, a mouthpiece which is attached to one end of a hose connected to the gas supply unit is press-fitted onto the communicating section, with the aid of an O-ring on the inner peripheral surface of the mouthpiece. In this case, however, if an unexpected external force is applied to the endoscope or hose, in the middle of the leakage check, the mouthpiece may be easily disconnected from the communicating section.
Thereupon, a connecting device for connecting a gas supply unit to a gastight endoscope is conventionally proposed, which device comprises a communicating section for connecting the inside and outside of the endoscope; a retainer protruding from the outer peripheral surface of the communicating section; and a gas supply side connector having an engaging slit which engages with the retainer, being connected to a hose of the gas supply unit, and being securely connected to the communicating section, by engaging the retainer with the engaging slit (Japanese Utility Model Application No. 57-113549).
In this prior art connecting device, the communicating section and the connector are connected in the following manner. First, the retainer is fitted into the engaging slit of the connector which is located on the communicating section. Then, the connector is rotated in relation to the communicating section so that the retainer is located at the extreme end of the engaging slit. Thereafter, the connector is further rotated so that the retainer moves in relation to the communicating section, pressed by the extreme end portion of the engaging slit. As the retainer moves in this manner, a valve in the communicating section is opened. As a result, the interior of the endoscope is connected to the gas supply unit. In removing the connector from the communicating section, the connector is rotated in the direction opposite to the direction of the connection, until the other end of the engaging slit abuts against the retainer. In this position, the connector is ready for removal from the communicating section. In closing the valve, the connector is further rotated so that the retainer is moved by the other end of the engaging slit.
In the connecting device of this type, however, the connecting function of the connector is not entirely associated with the valve's opening and closing actions. In the position where the retainer is in contact with the other end of the engaging slit of the connector, the connector is ready for the removal from the communicating section although the valve is open. Therefore, if an unexpected force is applied to the connector in the middle of the leakage check, the connector will possibly rotate to the aforesaid position to be disengaged from the communicating section. Since the valve is then open, the water for the leakage check will enter the endoscope through the communicating section. Since the retainer interlocking with the valve projects from the communicating section, an external force may act on the retainer to move the same, thereby opening the valve during, e.g., transportation of the endoscope. If a user, unaware of these circumstances, washes the endoscope, the aforementioned trouble will occur.